Monitoring systems for monitoring of physiological parameters of a living being are well known in prior art. For example, PCT/IL2010/000774, the disclosure of which is included herein by reference in its entirety, discloses a health monitoring system that continuously checks the wellbeing of a person (or any other living being) that, typically, is considered healthy (or with a known set of diseases), covering a significant range of health hazards that may cause a significant life style change/limitation, and provides an alert as early as possible—all this, with no significant limitation to the normal life style of the person bearing the system.
Unlike conventional gel electrodes, which are directly applied to the living being's skin, using a conductive gel, textile electrodes are dry contact sensors adapted for use in measuring ECG signals and other vital signals such (EEG), electroencephalogram (EOG), electrooculogram and other medical measurements on the skin without any skin preparation, such as needed with wet electrodes, for example, shaving hairy skin.
To improve the performance of conventional wet ECG sensors and to be able to conduct continuous long term monitoring, a textile substrate is used to develop dry textile electrodes for sensing physiological parameters of a living being such as ECG signals. One such textile electrodes are disclosed in U.S. provisional application 61/729,548 filed Nov. 24, 2012, and in follow up applications depending thereon, such as PCT application PCT/IL2013/050963.
There is however a need to transfer the sensed electrical signals vertically along the knitted product and across knitted line segments, to a processing unit, preconfigured to process the sensed signal.
The term “seamless”, as used herein with conjunction with a wearable device, refers to a device that when worn by an average person, wherein the device puts no significant limitation to the normal life style of that person and preferably not seen by anybody when used and not disturbingly felt by the user while wearing it. Furthermore, no activity is required from the monitored person in order for the system to provide a personal-alert when needed. It should be noted that people that pursue non-common life style, such as soldiers in combat zone or in combat training zone, or firefighters in training and action, or athletes in training or competition may utilize non-seamless devices. As the “seamless” characteristics refers also to the user's behavior, the wearable component is preferably an item that is normally worn (e.g., underwear) and not some additional item to be worn just for getting the alert.
The terms “underwear” or “garment”, as used herein with conjunction with wearable clothing items, refers to seamless wearable clothing items that preferably, can be tightly worn adjacently to the body of a monitored living being, typically adjacently to the skin, including undershirts, sport shirts, brassiere, underpants, special hospital shirt, socks and the like. Typically, the terms “underwear” or “garment” refer to a clothing item that is worn adjacently to the external surface of the user's body, under external clothing or as the only clothing, in such way that the fact that there are sensors embedded therein, is not seen by any other person in regular daily behavior. An underwear item may also include a clothing item that is not underwear per se, but still is in direct and preferably tight contact with the skin, such as a T-shirt, sleeveless or sleeved shirts, sport-bra, tights, dancing-wear, and pants. The sensors, in such a case, can be embedded in such a way that are still unseen by external people to comply with the “seamless” requirement.
The terms “course” and “line segment”, are used herein as related terms. The tubular form of the garment is knitted on a knitting machine, such as a Santoni knitting machine, where the tubular form is knitted in a spiral having substantially horizontal lines. A single spiral loop/circle us referred to herein as a course and a portion of a course is referred to as line segment.
The term “vertical conductive trace”, is used herein, refers to knitting a lead wire, made of conductive yarns, and capable of transferring electrical signals across knitted line segment.
The phrase “clinical level ECG”, as used herein with conjunction with ECG measurements, refers to the professionally acceptable number of leads, sensitivity and specificity needed for a definite conclusion by most cardiology physicians to suspect a risky cardiac problem (for example, arrhythmia, myocardial ischemia, heart failure) that require immediate further investigation or intervention. Currently, it is at least a 12-leads ECG and preferably 15-lead ECG, coupled with a motion/posture compensation element, and a real-time processor with adequate algorithms.
One of the main technical challenges in using dry textile electrodes that are knitted integrally with tubular form garments, used for sensing electric and other physiological parameters, is in transferring clinical level ECG and/or other sensed signals from the textile electrodes, along the knitted fabric, to a selected area, in particular between adjacent knitting courses in the vertical direction, where conductivity may be impaired.
There is therefore a need to develop conductive mean that are built into the knitted fabric as part of the fabrication of the garment, wherein the conductivity, in particular between adjacent knitting courses in the vertical direction, can support the transfer clinical level of ECG signal from a textile electrode, along the fabric, to a selected area in the garment preconfigured to host a processing unit.
The good conductivity should prevail when the fabric is stretched to different directions during wearing.
The good conductivity should prevail after a preconfigured number of washes, including in a washing machine.
The good conductivity should prevail in any knitting design, location and shape in the fabric, including in diagonal lines, with respect to the knitting course direction.
The good conductivity should prevail when using any type of basic fabric yarns (cotton, manmade yarns, synthetic yarns, etc.).
There is therefore a need and it would be advantageous to provide a knitting method for knitting vertical conductive traces embedded into a knitted garment having a tubular form at preconfigured locations, transferring ECG or other signals from textile electrodes to a selected area of the garment.